docs-lint: validate catalog status vocab and family-reference cross-repo fields #46

scripts/docs-lint.mjs validates type, capability, and audiences against
controlled vocabularies and checks path/related resolution, but it does not
check two things the standard cares about:

1. status vocabulary. status is only checked for presence. Entries use
   current, proposed, archived, etc. with no enforced set, so a typo
   (currnet) passes. Add a controlled STATUSES set.

2. family-reference cross-repo fields. docs/DOCUMENTATION_POLICY.md §9
   says type: family-reference entries MUST carry authored_home,
   runtime_owner, consumers, and compatibility_status. The gate doesn't
   enforce it; a family entry missing those passes today.

Both are cheap additions to the existing per-entry loop and would catch the
exact class of drift this documentation audit had to find manually.